Zn(2,3,7,8,12,13,17,18-octaethylporphyrin) [triplet] excited state quenched by Hexachlorobenzene

Zn(2,3,7,8,12,13,17,18-octaethylporphyrin) [triplet] quenched by Hexachlorobenzene at conc. (1-50) x 10^–5 mol L^–1
Solvent : Benzene, 25ºC

k_q = 4 x 10⁷(L mol^–1 s^–1)
Activation energy = 46 (20-78ºC)(kJ mol^–1)

Mechanism: exciplex formation
Experimental methods: conventional flash, absorption, single shot signal
Comments: nonlinear Stern-Volmer plot at higher [Q]